1. Field of the Invention
The present invention relates to an integrally formed casing for a heat-dissipating fan. In particular, the present invention relates to a heat-dissipating fan casing that is integrally formed by means of punching a magnetically conductive plate to reduce the number of parts of the casing and the stator, to reduce an overall thickness, and to simplify the structure of the heat-dissipating fan.
2. Description of Related Art
FIG. 8 of the drawings illustrates a conventional heat-dissipating fan with an axial winding. The heat-dissipating fan includes a casing 10, a coil assembly 20, a rotor 30, a circuit board 40, a metal axle tube 50, an upper pole plate 60, and a lower pole plate 70. The casing 10 includes a plurality of ribs 11 connected to a base 12 on which the metal axle tube 50 is fixed. The circuit board 40 and a bobbin 21 of the coil assembly 20 are mounted around the metal axle tube 50. The upper and lower pole plates 60,70 are mounted to two sides of the bobbin 21 and each includes a plurality of pole arms that extend to form a plurality of magnetic pole faces 61. The rotor 30 includes a shaft 31 rotatably extended through a bearing (not shown) mounted in the metal axle tube 50. A change in the polarities of the magnetic pole faces 61 drives the rotor 30 to turn, thereby generating air current by the blades 32 on the rotor 30. However, there are too many parts of the stator (including the coil assembly 20, the bobbin 21, the circuit board 40, the metal axle tube 50, and the upper and lower pole plates 60,70. The parts of the stator are stacked on the base 12 and thus increase an overall thickness and overall volume of the heat-dissipating fan. As a result, such a heat-dissipating fan cannot be used in notebook type computers as well as other delicate electronic devices.